Tubular Beads and the Secrets of Offing

Unearthing Ancient Treasures: Tubular Beads and the Secrets of Offing 

Hidden within the annals of history, there are treasures that offer a glimpse into the past, providing us with invaluable insights into the lives of our ancestors. One such treasure, discovered in the hunter-gatherer site of Offing, nestled on the islet bearing its name in the magnificent Magellan Strait of Patagonia, Chile, is a testament to the ingenuity and craftsmanship of those who once called this place home. 

The remarkable discovery in Offing takes the form of tubular beads meticulously crafted from bird bone, specifically the ulna epiphysis. These intricate archaeological artifacts offer a tantalizing connection to a bygone era, where every piece tells a story, and every artifact unveils a mystery. 

To fully appreciate the intricate details and craftsmanship of these ancient beads, modern technology has played a vital role. A detailed stereo-microscope image, captured using a Moticam S6 with a magnification of 10x, offers an up-close and personal look at these delicate remains. This image, a testament to the harmonious marriage of technology and archaeology, was made possible by the skilled eye of José-Miguel Tejero. The specimen, a gracious contribution from Marianne Christensen and Dominique Legoupil, has provided a rare opportunity to explore the past with remarkable clarity. 

Fig .- Tubular Beads on bird bone | Moticam S6 10X

Image Credit: Dr. José Miguel Tejero

The hunter-gatherer site of Offing has long been a site of fascination for archaeologists and historians. The islet's remarkable location, surrounded by the captivating beauty of the Magellan Strait, is a fitting backdrop for the secrets it holds. The tubular beads found here, created with precision and care, are not only a testament to the skills of the individuals who once resided in this region but also a bridge connecting us to their daily lives and traditions.  

In a world that is ever-evolving, where technology continues to shape our future, it is humbling to see how the past and present can converge. The detailed stereo-microscope image of these ancient tubular beads serves as a reminder that even the smallest fragments of history can offer profound insights into the human experience. Thanks to the dedication of archaeologists, historians, and the power of modern technology, we can embark on a journey through time and connect with our ancestors in a way that was once unimaginable. As we gaze upon the carefully crafted beads, we are reminded of the enduring legacy of Offing and the countless stories yet to be discovered in the folds of time. It is through such discoveries that we continue to enrich our understanding of the past and, in doing so, pay homage to the ingenuity of those who came before us.

Department of Evolutionary Anthropology

University of Vienna

© Dr. José Miguel Tejero

Steam Bubble Cavitation

Understanding Corrosion: Cavitation

Cavitation is a fascinating yet destructive phenomenon that can have a profound impact on the integrity of materials, particularly in steam systems. This article delves into the world of cavitation and its role in pitting corrosion, shedding light on how it can lead to significant damage to steam heater tubes and piping systems. 

 

Cavitation occurs when steam bubbles rapidly collapse, generating an extraordinary amount of pressure on the adjacent material. This can result in the formation of pin-sized to larger holes, which can ultimately lead to the leaking of steam heater tubes. The process is driven by the collapse of steam bubbles, creating a highly localized and intense pressure that causes damage to the material's surface. 

Fig 1.- Tube Inside Cavitation | Motic Panthera SMZ171, Moticam 10 Stack

Image Credit: Willem Cramer

Cavitation erosion is closely linked to the behavior of flash steam in the system. Flash steam occupies a relatively large volume but rapidly condenses when it loses heat, which is transferred through the tube wall into the surrounding fluid. This sudden condensation of flash steam results in a significant change in volume. 

The specific volume differences between steam and condensate are key to understanding cavitation's destructive potential. When flash steam condenses, it creates a large void that is swiftly and often violently filled by adjacent condensate. This rapid filling of the void generates shock waves known as water hammer. 

Fig 2.- Tube Outside Cavitation | Motic Panthera SMZ171, Moticam 10 Stack

Image Credit: Willem Cramer

The rapid collapse of the flash volume and the associated shock, caused by high-velocity condensate filling the void, can have severe consequences. The force generated by water hammer and the erosion caused by the swift filling of voids can result in significant damage to piping systems. In conclusion, cavitation is a complex phenomenon with the potential for significant damage in steam systems. The rapid implosion of steam bubbles, driven by specific volume differences between steam and condensate, can lead to the formation of holes and result in pitting corrosion. Understanding the mechanics of cavitation is crucial for preventing and mitigating the destructive consequences it can have on steam heater tubes and piping systems.

© willemsmicroscope.com

What’s in a rat?

The role of rodents in biomedical research is invaluable. Rodents, such as mice and rats, are the most commonly used mammals in biomedical research because of their anatomical, physiological and genetic similarities to humans. 

Scientists are able to genetically adapt mice to study a disease, for example by removing certain genes or by inserting (human) genes that are at the basis of certain disorders. For example, breast cancer can be simulated in mice to study the mechanisms of cancer and to test treatments. Mice and rats are also often used in behavioral studies to test, for example, treatments for memory loss in dementia.

Rodents are used in countless research areas, from cancer to immune diseases, heart disease, hypertension, metabolic and hormonal disorders, diabetes, obesity, osteoporosis, glaucoma, blindness, deafness, psychiatric disorders such as depression and schizophrenia, and neurodegenerative disorders such as Alzheimer's disease, Parkinson's and ALS.

The images taken with the new Moticam S6 camera show a cross-section with details through the upper body of the rat, just above the splice of the trachea into the two bronchi. The beautiful coup shows the various body parts in this cross section, some of which are indicated below.

With thanks to Cees Koopman, veterinarian.

© willemsmicroscope.com

Drill a hole before you can eat

The whelk or Buccinum undatum (Linnaeus, 1758) belongs to the snails (Gastropoda).

The whelk is a large, thick predatory snail with 7 or 8 turns. A deep seam runs between the turns. The mouth opening takes up almost half of the shell and ends in a sipho. On the surface there are horizontal ribs and clear vertical growth lines. Often there are also vertical ribs at the top of the shell. It grows up to 11 cm high and 7 cm wide. The whelk has yellowish-white with dark spots. Whelks washed ashore are often dark blue, because they have been lying on the bottom of the sea for a long time.

The yak keeps you warm and tidy in the winter

The yak is a bovine species, that lives amongst others in Tibet. They graze in the cool higher part of mountainous areas. Yaks are not adapted to living in hot climates. The main raw material produced by the yaks is wool, existing of tail hair and long hair along the yak belly. Yak shearing takes place in the spring, which is a difficult action because of the furious personality of this animal. 

Multipurpose symbiosis

The black alder - Alnus glutinosa - lives in symbiosis with bacteria from the actinomycetes group. These are capable of withdrawing nitrogen from the atmosphere. Through this partnership, the alder, despite its relatively high nutritional requirements, can colonize nitrogen-poor locations.

Wormwood fluorescence

The photos we see here were taken from a Plescher prepared slide. Plescher fluorescence prepared slides are characterized by a distinctive, three-dimensional, deeply structured honeycomb structure. This is made possible by special, complex, gentle pre-treatment of the hand coupes made of living material that reproduce the sensitive cell contents surprisingly well. The conventional ultra-thin section technology with embedding in paraffin, does not provide the same detailed results. Plescher specimens impress with their specially developed Plescher staining with clarity and gloss, differentiated on a deep black background at 460 - 490 nm excitation wavelength. They are therefore generally ideal for photo stacking.

How to avoid extreme highlights from reflecting surfaces

Optimize your illumination system. Extremely applicable in case of image documentation by a digital camera.

Reflected light is polarized light. This physical property is known by everybody who is doing serious photographies with a single lens reflex camera.

Motif: Landscapes, technical buildings, any kind of documentation for newspaper or book.
Solution: A rotatable polarization filter mounted in front of the objective.

Polarization filter of a reflex camera (source)

Rotate the filter until contrast is maximum, reflections are minimum. A new viewing angle requires a new adjustment.

Picture taken with Pol-Filter, interior visible vs Picture taken without Pol-Filter (source)

Ithytrichia lamellaris: ‘Not observed in a hundred years’

In a little stream in Limburg, the southernmost province in the Netherlands, an apparently unknown animal was unexpectedly found by members of the Macrofauna Workgroup Green Hearth Leudal. During the determination an animal with a very remarkable shape was noticed in a partly transparent tube, which was no larger than 4 mm. The segments of the abdomen of the animal were lobed like bellows of an accordion. In addition, there was a drop-shaped appendix on each lobe. This had to be something very special. Internet gave little to no result. Until an article with a photo attracted attention. In the photo you could see an animal that looked like the captured one. The headline: ‘Not observed in a hundred years’, indicated that something strange might have been caught?

What makes a human tooth

The images of a cross-section of the root of a tooth (a ground preparation) show various details of the structure of a tooth. Many of the visible details will not be discussed here. To go more deeply, scientific literature is available.

Pollen bring light into the darkness

A way of classifying pollen species is by monitoring auto fluorescence images of pollen grains. Several components of the exine (i.e. the outer layer of the pollen wall) show conspicuous auto fluorescence in the pollen grain.

Silverberry and the universe

A prepared slide of Silverberry scaly hair is often found in microscopy starters packages for amateurs. The beautiful colors and shapes do well under the microscope.

Basics of Light Microscopy: Incident Light Microscopy for opaque samples (I)

A closer look on Incident Light Microscopy reveals a new and noticeable fact. In a compound microscope for opaque samples, the objective plays two roles. First, like in a Transmitted light setup the objective is part of the imaging process. Quality and performance of the objective are essential elements to get reliable and “close-to-truth” results. 

Secondly, the objective additionally is part of the illumination system. Light from the lamp house passes the illumination axis and is deflected by a 45° orientated semi-transparent mirror. Sent through the objective, the light is reflected by the sample surface and brings back sample information to the eyepieces/camera. For a beginner it is difficult to accept that both illumination and imaging processes do not interfere visually. 

About Polarization

Utilizing the polarization method in light microscopy reveals a specific kind of information about the sample. Applying this contrast method, we less often talk about structure size and shape, resolution power or even a specific staining. In case of transparent samples, polarization contrast in first instance has one subject in mind: the potential BIREFRINGENCE of the sample and its implications on a structural insight.

BIREFRINGENCE is a widespread phenomenon, found in nature as well as in man-made materials. Starch grains, fibers, crystals and minerals, plastic sheets and die cast components, the structural basis is always the same: embedded within an amorphous matrix, structures with an intrinsic geometric pattern cause an impact on the speed of light and its oscillating direction when sent through the sample.

Chemical cristals